Medical washers are conventionally known and are used to clean instruments and equipment that are exposed to biological contaminants. Such washers typically clean the instruments and equipment by directing jets or streams of fluid at the instrument and/or equipment from spray heads or nozzles located within the washer. A typical cleaning operation may include a preliminary rinse cycle, a pre-wash cycle, and a wash cycle (where the instruments and equipment are exposed to one or more chemical cleaning solutions), a rinse cycle and a thermal rinse cycle.
During these various phases of a washing cycle, fluids are introduced into the washing chamber by pumps to effect the washing or rinsing of the articles to be cleaned. The fluids used within the washing chamber during the different cycles often have significantly different temperatures. For example, during a pre-wash phase, cold water from a facility's cold water lines (i.e., tap water) is typically used. The wash phase typically uses water from the facility's water lines (with added detergents and chemicals), the water being heated within the washing chamber to about 150° F. (The heating of fluids within the washer typically occurs in a sump located at the bottom of the washing chamber where the washing fluids are collected). The rinse phase typically uses hot water from the facility's hot water line. A thermal rinse typically uses pure, high-quality water that is heated within the washer to about 190° F.
It is known to heat the fluids used in a medical washer using electric-heating systems or steam-heating systems. The use of electric-heating systems generally produces longer cycle times and lower performance because electricity cannot economically be used at the levels necessary to provide the desired heating. Steam is more economical, but the use of steam in medical washers presents other problems. In this respect, fewer and fewer medical facilities have steam systems available, let alone steam systems that can provide high-quality steam that is required in medical washers. Moreover, the steam condensate, which results after steam is used in the heat exchanger, is often merely directed to a drain in the building's facilities. In one respect, this represents a loss of energy. In another respect, cold potable water is often used to cool down the steam condensate to a temperature acceptable for discharge to a drain. This further consumes another valuable resource.
The present invention provides a washer/disinfector having a steam-heating system for heating fluids used in the washer/disinfector wherein residual steam and steam condensate are exhausted from the steam-heating system into the washer/disinfector.